1. Field of the Invention
This invention relates to a stopper head. It also relates to a stopper for a container, like what is used to seal a bottle.
2. Description of the Related Art
There are stoppers that comprise a cylindrical portion made of cork or a synthetic material, also called a stopper body, one end of which is secured to a plastic head by gluing.
These stoppers for the food industry must meet very strict standards.
However, the use of glues that are suitable for contact with food cannot guarantee due to the limitations of their chemical composition full adhesion in an environment that is subject to extreme conditions.
There have been attempts to solve this problem by providing, successively:                stoppers whose bond between the stopper head and body is enhanced by a solid cylindrical element that protrudes and enters into a blind hole in the stopper body,        stoppers without glue, whose bond between the stopper head and stopper body is formed by overmolding.        
However, it is often observed that the stopper body separates from the head when opening a bottle fitted with such a stopper because of adhesion problems between these elements.
During use, this assembly is effectively subject to tensile mechanical stress, which could result in tearing the stopper head.
The strength of the bond, or attachment, between the stopper body and the stopper head must therefore be increased.